have you studied in this school?For about two years.A. How oftenB. How longC. How

问题补充：

--- have you studied in this school?

--- For about two years.

A. How often

B. How long

C. How much

D. How many

答案：

A. How often

(答案→)B. How long

C. How much

D. How many

解析：How often多久一次；How long多长；How much多少钱；How many多少个。根据下文，大约两年。可知上文提问的是时间长短，故选B。